From b5dc608c98d929abbf2fe932ed07b3c868d83342 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 20 Oct 2010 20:59:57 +0100 Subject: [PATCH] drm/i915: Copy the updated reloc->presumed_offset back to the user If the userspace driver is using a constant relocation array with a static buffer, they will pass the same relocation array back to the kernel. So we *do* need to update the presumed offset value in those relocations to reflect the current object so that they remain correct with future batchbuffers and we avoid the necessity of having to suspend execution and perform redundant relocations. Fixes the regression introduced by 12f889c for applications using absolute addressing on trees of buffer (i.e. the current consumers of libdrm_intel.so). Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=30996 Reported-by: Wang, Jinjin Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/i915_gem.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 6e85496f9164..5041ebe3fdf9 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3399,6 +3399,15 @@ i915_gem_execbuffer_relocate(struct drm_i915_gem_object *obj, iowrite32(reloc.delta, reloc_entry); io_mapping_unmap_atomic(reloc_page, KM_USER0); } + + /* and update the user's relocation entry */ + reloc.presumed_offset = target_offset; + if (__copy_to_user_inatomic(&user_relocs[i].presumed_offset, + &reloc.presumed_offset, + sizeof(reloc.presumed_offset))) { + ret = -EFAULT; + break; + } } drm_gem_object_unreference(target_obj); @@ -3560,6 +3569,10 @@ validate_exec_list(struct drm_i915_gem_exec_object2 *exec, if (!access_ok(VERIFY_READ, ptr, length)) return -EFAULT; + /* we may also need to update the presumed offsets */ + if (!access_ok(VERIFY_WRITE, ptr, length)) + return -EFAULT; + if (fault_in_pages_readable(ptr, length)) return -EFAULT; } -- 2.20.1